Tests: execute all notebook cells

[trey-stafford]

GHA are currently setup to test that quarto can render the notebooks. As presently defined, the call to quarto render simply renders the notebooks into HTML - it does not execute the code defined in the notebook cells.

We should consider tweaking the call to quarto render to include --execute so that all cells are tested. At a minimum, this should be done in a local environment and identified errors corrected. I did so and encountered a number of issues, including undefined variable names (see the attached error log, or reproduce locally).

render-execute-error-log.txt

The complication with running render with --execute in GHA is that it can take a while (several minutes - not sure exactly) and we may need access to EDL credentials.

Finally, one other thing we may want to change about the quarto render test, is to include the SnowEx notebooks, which are currently excluded (not sure why).